CORVALLIS, Ore. — The Colorado Buffaloes wiped the rust off a three-week layoff Saturday, and what did they find? Grasping for positive straws in the drizzle and wind, they were not the 1-11 Buffaloes circa 2012. However, the Buffs of a 2-0 September were nowhere to be found either.

Instead, an ineffective offense all but forgot about the nation’s most prolific receiver, a defense wilted against the nation’s most prolific passer and the special teams again were anything but special.

It all added up to a 44-17 drubbing at the hands of Oregon State, which gave first-year Colorado coach Mike MacIntyre a cold, wet, “welcome to the Pac-12” slap in his league opener.

“We have the talent to play with Oregon State,” MacIntyre said. “There’s no doubt in my mind.”

That debate is moot for now. Regardless of the talent, no team can win if its star player — in this case, CU’s Paul Richardson — catches one pass for 2 yards in the first half. No team can bounce back from fumbling two kickoff returns in the third quarter when the Beavers’ Sean Mannion is heating up on his way to a school-record six touchdown passes.

Oregon State (4-1, 2-0 Pac-12) went Oregon Ducks all over the Buffs, outgaining them 540 yards to 300. Mannion threw for 414 yards. CU’s Connor Wood was a frosty 14-of-34 for 146 yards, two touchdowns and two interceptions.

When the floods hit Boulder, MacIntyre not only worried about his eight displaced players but also the potential rust when his Buffs finally felt an opponent’s hit and a crowd’s roar. But he didn’t blame the wait or the wind.

Saturday’s game already was slipping away from the Buffs. Mannion opened the second half with a drive culminating in a 22-yard TD pass to Brandin Cooks for a 24-3 lead. Trying to claw back, Marques Mosley returned the ensuing kickoff but Oregon State’s Zack Robinson knocked the ball forward and kicker Trevor Romaine recovered for the Beavers.

One more Mannion touchdown pass later, a squib kick bounced off the flailing hands of Brady Daigh and the Beavers recovered again. That set up Mannion’s fifth TD pass, a simple 4-yarder to Caleb Smith to make it 38-3.

Game. Set. Light the match.

“We work on catching squib kicks and bloops,” a visibly perturbed MacIntyre said. “We even send our kids out early before the game to handle that.”

CU’s defense held Mannion in check in the first half, when the Buffs trailed only 17-3. But Richardson, leading the nation with an average of 209 receiving yards per game, fell short of that in the first half by 207. Oregon State shadowed him, but this is the same defense that hadn’t shown much of a pulse until the second half the week before at San Diego State.

“We got it to him in the second half,” MacIntyre said of Richardson. “We should’ve thrown it to him more.”

By the second half, it was too late. CU’s defense couldn’t handle Mannion or Cooks, who was one-two nationally with Richardson in receptions per game entering the weekend. That mini-battle turned into a slaughter. Richardson finished with five catches for 70 yards and a touchdown.

Cooks finished with nine catches for 168 yards and two TDs.

“They didn’t hold up,” Mac- Intyre said of the Buffs defensively. “We gave up (540) yards. You can’t be doing that. We should’ve had three picks. We’re double-covering a kid. We’re all over him and we don’t make the play. We’ve got to make the play.”

The Buffs had better start making more. Coming to town next Saturday is second-ranked Oregon. At least Wood doesn’t appear to be heading down the dark elevator shaft the Buffs occupied last year.

“You can’t look at this as a failure at all,” Wood said. “You’ve got to look at it as a learning experience.”